I have Norton Internet Security 5.3 on my iMac (OS 10.8.2). And I got those error messages: "Liveupdate had an error starting up. Please try again." and "Norton AntiVirus could not open its preferences." and "Settings background application is not running." (when attempting to open Norton Internet Security application.
I have rebooted, uninstalled and reinstalled but I get the same result. I also have dowloaded and run the "special" uninstaller. It did not work either. I ran the Disk Utility to repair permissions, it didn't work again. :o(